Unexpected algae bloom hits Patong beach due to premature seaweed growth

Yesterday, employees from the Public Health and Environment Division of Patong Municipality were hard at work on Patong Beach, clearing off algae that washed ashore. This unexpected event came as a result of an algae bloom and has yet to be formally addressed by Patong Municipality.

The purpose of this timely response was primarily to retain the aesthetic appeal of Patong Beach. If neglected, the algae could not only generate a foul odour but also tarnish the appealing image of the beach, which is a major attraction for tourists in Phuket.

Interestingly, the report disclosed that such algae blooms are a recurring phenomenon at Patong Beach, typically observed from the end of January through to March each year. However, this year the algae bloom occurred somewhat prematurely. The report noted that on any given day, workers can gather more than a tonne of this seaweed, with the maximum amount collected this time being around 3 tonnes.

The peculiar physical attributes of Patong Bay contribute to this situation. The bay’s deep concave shape slows down the water flow from Pak Bang Canal into the bay, especially around this time of year. Moreover, the absence of strong winds and waves during the southwest monsoon results in the water from Pak Bang Canal mixing with the beach water, where many tourists enjoy swimming, reported NBT Phuket.

The report further explains that under suitable sunlight conditions, this mix can trigger abnormal algae growth, which exceeds the natural elimination capacity. However, the report failed to highlight the pollution levels and the volume of untreated wastewater continually flowing into Patong Bay from the Pak Bang Canal.

Data on coastal water quality in Phuket, including Patong, is no longer made public by the Pollution Control Department’s Environment and Pollution Office 15 (EPO15). The agency’s most recent reports vaguely categorise the water quality as fair or good without providing further details.

Additionally, EPO15 has stopped releasing its Source of Pollution Report. The latest available report only displays a generalised graph with data from 2021. The agency has also ceased to share its latest Community Wastewater Treatment Plant Report, providing only annual and seasonal averages for previous years.

During a visit to Phuket in September, Dr. Surasee Kittimonthon, Secretary-General of the Office of National Water Resources (ONWR), revealed that Phuket discharges nearly 55,000 cubic metres of untreated wastewater daily. The Patong Municipality Wastewater Treatment Plant can treat up to 39,000 cubic metres of wastewater per day. Further expansion would necessitate a substantial budget, he was informed. During his visit, Dr. Surasee witnessed the distressing sight of dark, untreated wastewater flowing into the Pak Bang Canal and entering the beach water, where tourists were playing.